Vibrating micromechanical sensor of angular velocity

ABSTRACT

The invention relates to measuring devices to be used in the measuring of angular velocity and, more precisely, to vibrating micromechanical sensors of angular velocity. In a sensor of angular velocity according to the invention, a mass is supported to the frame of the sensor component by means of an asymmetrical spring structure ( 1 ), ( 2 ), ( 3 ), ( 4 ), ( 22 ), ( 24 ) in such a way, that the coupling from one mode of motion to another, conveyed by the spring ( 1 ), ( 2 ), ( 3 ), ( 4 ), ( 22 ), ( 24 ), cancels or alleviates the coupling caused by the non-ideality due to the skewness in the springs or in their support. The structure of the sensor of angular velocity according to the invention enables reliable measuring with good performance, particularly in small vibrating micromechanical solutions for sensors of angular velocity.

FIELD OF THE INVENTION

The invention relates to measuring devices to be used for measuringangular velocity and, more precisely, to vibrating micromechanicalsensors of angular velocity. The object of the invention is to providean improved sensor structure enabling reliable measuring with goodperformance, particularly in small size vibrating micromechanicalsolutions for sensors of angular velocity.

BACKGROUND OF THE INVENTION

In measuring angular velocity, the principle of the method of measuringbased on a vibrating sensor of angular velocity has proved to be simpleand reliable. In a vibrating sensor of angular velocity, a certain knownprimary motion is induced and maintained in the sensor. The desiredmotion to be measured by means of the sensor is then detected as adeviation of the primary motion.

An external angular velocity in a direction perpendicular to theresonators' direction of motion acting on the sensor induces a Coriolisforce in the seismic mass in a direction perpendicular to its directionof motion. The Coriolis force, proportional to the angular velocity, isdetected, for example capacitively, in the vibration of the mass.

One of the most significant problems in micromechanical vibratingsensors of angular velocity is the so called quadrature signal, which iscaused by poor dimensional precision in the structures. In resonatorsmanufactured using the means of micromechanics, there may be foundtolerance errors in the perpendicularity of the directions of motion,which in the detection of the sensor of angular velocity cause a signal,called the quadrature signal, of a magnitude, at worst, hundreds oftimes larger than the angular velocity signal corresponding to themaximum value of the output scale.

The angular velocity signal to be measured, being proportional to thespeed of the mass, is luckily phase-shifted by 90 degrees in relation tothe quadrature signal, whereby the quadrature signal disappears in anideal demodulation. However, being significantly larger than the signalto be measured, it restricts the dynamics of the signal. Another bigdisadvantage of the quadrature signal is, that it, if left uncompensatedfor, significantly degrades the stability of the zero point of thesensor, due to phase shifts in the electronic signals as, for example,the temperature changes.

In the sensor, the quadrature signal can be compensated for by usingelectric forces. One of the known techniques is i.a. feed-forwardcompensation, in which a force modulated by the detected primary motionis fed back into the detecting resonator at a phase opposite to thequadrature signal. Alternative ways of electrical compensation include,for example, straightening of the direction of motion by a staticelectric force or by a force generated by a static entity modulated bythe motion, which force compensates for the quadrature signal caused bya residual of the spring force.

Compensation by means of electric forces constitutes a challenge to thesensor's electronics. What is required is either accurate phase controlor, possibly, large voltages and separate structures within the sensor.

Thus, the object of the invention is to provide a structure of avibrating sensor of angular velocity, in which the compensation for thequadrature signal is implemented directly by mechanical design, withoutelectric forces.

Referring to prior art, the Finnish patent publication FI-116543B1describes a sensor of angular velocity according to prior art, where theseismic masses are connected to support areas by springs and/or stiffauxiliary structures, which give the masses a degree of freedom inrelation to an axis of rotation perpendicular to the plane of the diskthey are forming, and to at least one axis of rotation extending in thedirection of the plane of the disk.

Further, referring to prior art, the Finnish patent publicationFI-116544B1 describes a sensor of angular velocity according to priorart, where at least one pair of electrodes is formed in association withthe edge of the seismic mass, which pair of electrodes forms twocapacitances with the surface of the mass, so that, as a function of theangle of rotation of the mass's primary motion, one capacitance of thepair of electrodes increases and the other capacitance of the pair ofelectrodes decreases.

SUMMARY OF THE INVENTION

The objective of the invention is to provide such an improved vibratingsensor of angular velocity, which enables reliable measuring with a goodperformance, particularly in solutions with a small vibrating sensor ofangular velocity, and in which the compensation for the quadraturesignal is implemented by mechanical design without electriccompensation, or, alternatively, in combination with the electriccompensation methods mentioned above.

According to a first aspect of the invention, a vibratingmicromechanical sensor of angular velocity is provided, which comprisesat least one seismic mass and, associated with the mass, a movingelectrode, which mass possesses a primary motion, which is to beactivated, and, in addition to the primary motion, at least one degreeof freedom in relation to a detection axis, or detection axes,essentially perpendicular to the primary motion, and which mass, orwhich masses, is/are supported to the frame of the sensor component bymeans of a spring structure such, that the spring structure isasymmetric such, that the coupling, conveyed by the spring, from onemode of motion to another cancels or alleviates the coupling caused bynon-ideality due to skewness of the springs or their support.

Preferably, one corner of the spring structure is etched off.Alternatively, one or more compensation groove is etched into the springstructure. Further, alternatively, one or more compensation cavity isetched into the spring structure. Further, alternatively, one or morecompensation groove or compensation cavity is etched into at least oneattachment spot for the spring structure. Further, preferably, thecompensation grooves or the compensation cavities are suitablydimensioned such, that they effectively straighten the end portion of askewed spring.

Alternatively, one edge of the spring structure is serrated.Alternatively, both edges of the spring structure are serrated. Further,preferably, the serration is suitably dimensioned to be one-sided orasymmetric such, that the serration twists the bending axis of thespring.

Preferably, the spring structure is designed to be asymmetric such, thatthe coupling from one mode of motion to another, conveyed by the spring,cancels or alleviates the coupling caused by non-ideality due to aninclination relative to the perpendicular to the disk of the groove ofthe DRIE etching process.

According to a second aspect of the invention, a method is provided formanufacturing, by means of micromechanical disk structures, a vibratingmicromechanical sensor of angular velocity comprising at least oneseismic mass and, in association with the mass, a moving electrode,which mass possesses a primary motion to be activated and, in additionto the primary motion, at least one degree of freedom in relation to adetection axis, or detection axes, essentially perpendicular to theprimary motion, and which mass, or which masses, is/are supported to theframe of the sensor component by means of a spring structure such, thatthe spring structure of the sensor of angular velocity is madeasymmetric by etching.

Preferably, the etching mask is designed such, that it compensates fornon-idealities occurring over the surface of the disk, caused by themanufacturing process. Preferably the DRIE etching technique (DRIE, DeepReactive Ion Etching) is used in the manufacturing. Preferably, in themanufacturing, non-idealities of the DRIE etching process are utilized,such as the ARDE effect (ARDE, Aspect Ratio Dependent Etch rate).Preferably, a two-stage DRIE etching process is utilized in themanufacturing, by means of which the depth of the etched groove orcavity can be suitably dimensioned.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, the invention and its preferable embodiments are described indetail with exemplifying reference to the attached drawings, of which:

FIG. 1 shows a section through a spring structure used in supporting theseismic mass of a vibrating sensor of angular velocity according to theinvention,

FIG. 2 shows a perspective view of the spring structure used insupporting the seismic mass of a vibrating sensor of angular velocityaccording to the invention,

FIG. 3 shows a section through an alternative spring structure used insupporting the seismic mass of a vibrating sensor of angular velocityaccording to the invention,

FIG. 4 shows a perspective view of the alternative spring structure usedin supporting the seismic mass of a vibrating sensor of angular velocityaccording to the invention,

FIG. 5 shows a perspective view of a second alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention,

FIG. 6 shows a perspective view of a third alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention,

FIG. 7 shows a perspective view of a fourth alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention,

FIG. 8 shows a perspective view of the structure of a vibrating sensorof angular velocity according to the invention,

FIG. 9 shows a perspective view of the structure of a vibrating sensorof angular velocity with two axes according to the invention,

FIG. 10 shows a perspective view of a fifth alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention,

FIG. 11 shows a perspective view of a sixth alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In a vibrating sensor of angular velocity according to the invention,the primary motion to be activated is the vibration of at least oneseismic mass and an associated moving electrode. In addition to theprimary motion, the seismic mass possesses another degree of freedom inrelation to a detection axis essentially perpendicular to the primarymotion.

Further, the sensor of angular velocity according to the inventioncomprises a seismic mass and an associated moving electrode, which massis supported to the frame of the sensor component by means of a springstructure.

The moving electrode in the primary motion mode of the vibrating sensorof angular velocity according to the invention is activated intovibration. Thus, the coupling caused by the Coriolis force activates thedetection motion mode. The motion axes of the primary motion mode andthe detection motion mode, or the detection motion modes, areessentially perpendicular to each other. Due to the known non-ideality,there will be a coupling between the modes in the absence of angularvelocity activation.

In one structure of a vibrating sensor of angular velocity according tothe invention, the primary motion to be activated is the vibration of atleast one seismic mass and an associated moving electrode.Correspondingly, the motion of the detection motion mode can then occur,for example, essentially in the plane of the disk. Alternatively, themotion of the detection motion mode can occur essentiallyperpendicularly to the plane of the disk.

The vibrating sensors of angular velocity according to the invention aretypically manufactured by means of disk structures. Typically amultitude of structures of sensors of angular velocity are manufacturedonto a central disk by means of, for instance, etching techniques, whichcentral disk then, for example, is sealed by disks on top andunderneath. The sensors of angular velocity are diced out of thefinished disk package structure.

In sensors having the structure of vibrating sensors of angularvelocity, manufactured by means of the DRIE etching technique (DRIE,Deep Reactive Ion Etching), in which sensors one mode of motion is inthe plane of the disk and the other is perpendicular to the plane of thedisk, the quadrature signal is caused by an inclination of the DRIEgroove in relation to the normal to the disk. The phenomenon is wellrepeatable and its distribution over the disk is known.

Since the distribution over the disk is known, compensation, accordingto the invention, of the structures of the vibrating sensors of angularvelocity can be implemented by means of the manufacturing mask, wherebythere will be no need for individual mechanical tuning of the structuresof the sensors of angular velocity.

The phenomenon causing the quadrature signal in the structure of thevibrating sensor of angular velocity according to the invention is aknown one, such as, for example, the quadrature signal caused by theinclination of the DRIE etching process groove in relation to the normalto the disk, and thus the quadrature signal distribution over the diskis also known and repeatable.

In the solution according to the invention, the quadrature signal iscompensated for by designing the springs to be asymmetrical such, thatthe coupling, conveyed by the springs, from one mode of motion toanother cancels or significantly alleviates the coupling caused by thenon-ideality due to the quadrature signal.

As a special case of the solution, a asymmetrical spring in thestructure, according to the invention, of the vibrating sensor ofangular velocity can be produced by using other non-idealities of theDRIE etching process. As examples of such non-idealities of the DRIEetching process, the ARDE effect (ARDE, Aspect Ratio Dependent Etchrate), and the wedge-like character of the profile, can be mentioned.Thus, compensation according to the invention is accomplished withoutany additional process steps.

The FIGS. 1 through 11 show examples of spring structures of thestructure of the vibrating sensor of angular velocity according to theinvention, by means of which spring structures the quadrature signal canbe compensated for.

FIG. 1 shows a section through a spring structure used in supporting theseismic mass of a vibrating sensor of angular velocity according to theinvention. The spring structure of the sensor of angular velocityaccording to the invention is depicted with the numeral 1. A corner ofthe spring structure 1 according to the invention is etched off. Thespring structure according to the invention is asymmetrical such, thatthe coupling, conveyed by the spring, from one mode of motion to anothercancels or significantly alleviates the coupling caused by non-idealitydue to the quadrature signal.

FIG. 2 shows a perspective view of the spring structure used insupporting the seismic mass of a vibrating sensor of angular velocityaccording to the invention. The spring structure of the sensor ofangular velocity according to the invention is depicted with by thenumeral 1. A corner of the spring structure 1 according to the inventionis etched off.

In manufacturing the spring structures according to the invention shownin FIGS. 1-2, the etching mask can be designed such that it compensatesfor non-idealities occurring over the disk caused by the manufacturingprocess. One of these non-idealities is, for example, the non-idealitycaused by the inclination of the DRIE etching process groove in relationto the normal to the disk. Thus, the size of the cut-off corner of thespring structure 1 according to the invention varies over the disk.

FIG. 3 shows a section through an alternative spring structure used insupporting the seismic mass of a vibrating sensor of angular velocityaccording to the invention. The alternative spring structure of thesensor of angular velocity according to the invention is depicted withthe numeral 2. One or more compensation grooves have been etched intothe alternative spring structure 2 according to the invention. Thealternative spring structure 2 according to the invention isasymmetrical such that the coupling, conveyed by the spring, from onemode of motion to another cancels or significantly alleviates thecoupling caused by non-ideality due to the quadrature signal.

FIG. 4 shows a perspective view of the alternative spring structure usedin supporting the seismic mass of a vibrating sensor of angular velocityaccording to the invention. The alternative spring structure of thesensor of angular velocity according to the invention is depicted withthe numeral 2. One or more compensation grooves have been etched intothe alternative spring structure 2 according to the invention.

In manufacturing the alternative spring structures 2 according to theinvention, shown in FIGS. 3-4, the etching mask can be designed suchthat it compensates for non-idealities occurring over the disk caused bythe manufacturing process. One of these non-idealities is, for example,the non-ideality caused by the inclination of the DRIE etching processgroove in relation to the normal to the disk. Thus, the dimensioning ofthe compensation groove of the alternative spring structure 2 accordingto the invention varies over the disk.

The compensation groove of the alternative spring structure 2 accordingto the invention can be etched in the same DRIE etching as the otherstructures. In manufacturing the alternative spring structures 2according to the invention, due to the ARDE effect, the compensationgroove would not be etched all the way through the disk, but rather, thedepth of the groove can be suitably dimensioned. Alternatively, a grooveof a suitable depth can, for example, be etched by means of a two-stageetching process.

FIG. 5 shows a perspective view of a second alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention. The second alternative springstructure of the sensor of angular velocity according to the inventionis depicted with the numeral 3. One or more compensation cavities havebeen etched into the second alternative spring structure 3 according tothe invention. The second alternative spring structure 3 according tothe invention is asymmetrical such that the coupling, conveyed by thespring, from one mode of motion to another cancels or significantlyalleviates the coupling caused by non-ideality due to the quadraturesignal.

In manufacturing the second alternative spring structure 3 according tothe invention, shown in FIG. 5, the etching mask can be designed suchthat it compensates for non-idealities occurring over the disk caused bythe manufacturing process. One of these non-idealities is, for example,the non-ideality caused by the inclination of the DRIE etching processgroove in relation to the normal to the disk. Thus, the dimensioning ofthe compensation cavities of the second alternative spring structure 3according to the invention varies over the disk.

The compensation cavities of the second alternative spring structure 3according to the invention can be etched in the same DRIE etching as theother structures. In manufacturing the second alternative springstructures 3 according to the invention, due to the ARDE effect, thecompensation cavities would not be etched all the way through the disk,but rather, the depth of the cavities can be suitably dimensioned.Alternatively, a groove of a suitable depth can, for example, be etchedby means of a two-stage etching process.

FIG. 6 shows a perspective view of a third alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention. The third alternative springstructure of the sensor of angular velocity according to the inventionis depicted with the numeral 4. The third alternative spring structureaccording to the invention comprises attachment spots 5, 6. One or morecompensation groove or compensation cavity have been etched into atleast one attachment spot 5, 6 of the spring structure 4. The thirdalternative spring structure 4 according to the invention isasymmetrical such that the coupling, conveyed by the spring, from onemode of motion to another cancels or significantly alleviates thecoupling caused by non-ideality due to the quadrature signal.

FIG. 7 shows a perspective view of a fourth alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention. The fourth alternative springstructure of the sensor of angular velocity according to the inventionis depicted with the numeral 7. The fourth alternative spring structure7 according to the invention comprises attachment spots 8, 9. One ormore compensation groove or compensation cavity have been etched intoboth attachment spots 8, 9 of the spring structure 7. The fourthalternative spring structure 7 according to the invention isasymmetrical such that the coupling, conveyed by the spring, from onemode of motion to another cancels or significantly alleviates thecoupling caused by non-ideality due to the quadrature signal.

In manufacturing the presented spring structures 4, 7, shown in FIGS.6-7, the etching mask can be designed such that it compensates fornon-idealities occurring over the disk caused by the manufacturingprocess. One of these non-idealities is, for example, the non-idealitycaused by the inclination of the DRIE etching process groove in relationto the normal to the disk. Thus, the dimensioning of the compensationgrooves or compensation cavities of the presented spring structures 4, 7varies over the disk.

The compensation grooves or compensation cavities of the springstructures 4, 7 shown in FIGS. 6-7 can be etched in the same DRIEetching as the other structures. In manufacturing of the presentedspring structures 4, 7, due to the ARDE effect, the compensation groovesor compensation cavities would not be etched all the way through thedisk, but rather, the depth of the grooves or cavities can be suitablydimensioned. Alternatively, a groove of suitable depth can, for example,be etched by means of a two-stage etching process. In the presentedspring structures 4, 7, suitably dimensioned compensation grooves orcompensation cavities effectively straighten the end portion of a skewedspring.

FIG. 8 shows a perspective view of the structure of a vibrating sensorof angular velocity according to the invention. The vibrating masses ofthe sensor of angular velocity according to the invention are depictedwith the numerals 10 and 11. The masses 10, 11 of the sensor of angularvelocity are supported at their attachment spots 12, 13 by means ofspring structures. At the opposite end 14 at the mass side of theattachment spot 12 of the spring structure of the sensor of angularvelocity or, alternatively, at the end 15 at the attachment spot 13 sideof the spring structure, one or more compensation grooves orcompensation cavities 14, 15 are etched. The spring structure of theinvention is asymmetrical such that the coupling, conveyed by thespring, from one mode of motion to another cancels or significantlyalleviates the coupling caused by non-ideality due to the quadraturesignal.

FIG. 9 shows a perspective view of the structure of a vibrating sensorof angular velocity with two axes according to the invention. Thevibrating mass of the sensor of angular velocity with two axes accordingto the invention is depicted with the numeral 16. The mass 16 of thesensor of angular velocity with two axes is supported at its attachmentspot 17 by means of spring structures. At the ends 18, 20 of the springstructure of the sensor of angular velocity with two axes, opposite tothe attachment spot 17, or, alternatively, at the ends 19, 21 at theattachment spot 17 side of the spring structure, one or two compensationgrooves or compensation cavities 18-21 are etched. The spring structureof the invention is asymmetrical such that the coupling, conveyed by thespring, from one mode of motion to another cancels or significantlyalleviates the coupling caused by non-ideality due to the quadraturesignal.

FIG. 10 shows a perspective view of a fifth alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention. The fifth alternative springstructure of the sensor of angular velocity according to the inventionis depicted with the numeral 22. One edge of the fifth alternativespring structure 22 according to the invention is serrated 23. The fifthalternative spring structure 22 according to the invention isasymmetrical such that the coupling, conveyed by the spring, from onemode of motion to another cancels or significantly alleviates thecoupling caused by non-ideality due to the quadrature signal.

In manufacturing the fifth alternative spring structure 22 according tothe invention, shown in FIG. 10, the etching mask can be designed suchthat it compensates for non-idealities occurring over the disk, causedby the manufacturing process. One of these non-idealities is, forexample, the non-ideality caused by the inclination, in relation to thenormal to the disk, of the DRIE etching process groove. Thus, thedimensioning of the serration 23 of the fifth alternative springstructure 22 according to the invention varies over the disk. Theserration 23 of the fifth alternative spring structure 22 according tothe invention can be etched in the same DRIE etching as the otherstructures.

FIG. 11 shows a perspective view of a sixth alternative spring structureused in supporting the seismic mass of a vibrating sensor of angularvelocity according to the invention. The sixth alternative springstructure of the sensor of angular velocity according to the inventionis depicted with the numeral 24. Both edges of the sixth alternativespring structure 24 according to the invention are serrated 25, 26. Thesixth alternative spring structure 24 according to the invention isasymmetrical such that the coupling, conveyed by the spring, from onemode of motion to another cancels or significantly alleviates thecoupling caused by non-ideality due to the quadrature signal.

In manufacturing the sixth alternative spring structure 24 according tothe invention, shown in FIG. 11, the etching mask can be designed suchthat it compensates for non-idealities occurring over the disk caused bythe manufacturing process. One of these non-idealities is, for example,the non-ideality caused by the inclination of the DRIE etching processgroove in relation to the normal to the disk. Thus, the dimensioning ofthe serrations 25, 26 of the sixth alternative spring structure 24according to the invention varies over the disk. The serrations 25, 26of the sixth alternative spring structure 24 according to the inventioncan be etched in the same DRIE etching as the other structures.

The DRIE etching profile in the spring structures 22, 24 shown in FIGS.10-11 is, in practice, in addition to the inclination, slightlywedge-shaped, i.e. the grooves widen in the depth direction, whereby theserration patterns differ between the upper and lower surfaces of thespring. In the solution according to the invention, the serration 23,25, 26 can be suitably dimensioned to be one-sided or asymmetrical,whereby the serration 23, 25, 26 twists the bending axis of the spring22, 24.

The solution according to the invention can be used for compensating forthe quadrature signal of all such sensors of angular velocity, in whichthe primary motion is a vibration of at least one seismic mass and anassociated moving electrode, and in which the mass, in addition to theprimary motion, possesses a second degree of freedom in relation to adetection axis, or detection axes, essentially perpendicular to theprimary motion.

1. A vibrating micromechanical sensor of angular velocity comprising atleast one seismic mass and an associated moving electrode, which masspossesses a primary motion, into which it has to be activated, and, inaddition to the primary motion, at least one degree of freedom inrelation to a detection axis, or detection axes, essentiallyperpendicular to the primary motion, and which mass is, or which massesare, supported to a frame of a sensor component by a spring structure,wherein the spring structure is asymmetrical such, that the couplingfrom one mode of motion to another, conveyed by the spring structure,cancels or alleviates the coupling caused by a non-ideality due toskewness in the spring structure or in its support.
 2. The sensor ofangular velocity according to claim 1, wherein a corner is etched offthe spring structure.
 3. The sensor of angular velocity according toclaim 1, wherein one or more compensation grooves are etched into thespring structure.
 4. The sensor of angular velocity according to claim1, wherein one or more compensation cavities are etched into the springstructure.
 5. The sensor of angular velocity according to claim 1,wherein one or more compensation grooves or compensation cavities areetched into at least one attachment spot of the spring structure.
 6. Thesensor of angular velocity according to claim 5, wherein thecompensation grooves or compensation cavities are suitably dimensioned,such that they effectively straighten the end portion of a skewedspring.
 7. The sensor of angular velocity according to claim 1, whereinone of the edges of the spring structure is serrated.
 8. The sensor ofangular velocity according to claim 1, wherein both edges of the springstructure are serrated.
 9. The sensor of angular velocity according toclaim 7, wherein the serration is suitably dimensioned to be one-sidedor asymmetrical, such that the serration twists the bending axis of thespring.
 10. The sensor of angular velocity according to claim 1, whereinthe spring structure is asymmetrically designed such, that the couplingfrom one mode of motion to another, conveyed by the spring, cancels oralleviates the coupling caused by the non-ideality due to theinclination of the groove of a DRIE (DRIE, Deep Reactive Ion Etching)etching process relative to a normal to a disk.
 11. A method for themanufacturing of a vibrating micromechanical sensor of angular velocityby micromechanical disk structures, which sensor of angular velocitycomprises at least one seismic mass and an associated moving electrode,which mass possesses a primary motion, into which it has to beactivated, and, in addition to the primary motion, at least one degreeof freedom in relation to a detection axis, or detection axes,essentially perpendicular to the primary motion, and which mass is, orwhich masses are, supported to a frame of a sensor component by a springstructure, wherein the spring structure of the sensor of angularvelocity is manufactured by etching to be asymmetrical.
 12. Methodaccording to claim 11, wherein a etching mask is designed such, that itcompensates for non-idealities occurring over a disk, caused by themanufacturing process.
 13. Method according to claim 11, wherein a DRIEetching technique (DRIE, Deep Reactive Ion Etching) is being used in themanufacturing.
 14. Method according to claim 11, wherein, inmanufacturing, non-idealities of the DRIE (DRIE, Deep Reactive IonEtching) etching process, such as the ARDE effect (ARDE, Aspect RatioDependent Etch rate), are being utilized.
 15. Method according to claim11, wherein, in manufacturing, a two-stage DRIE (DRIE, Deep Reactive IonEtching) etching process is being utilized, by which the depth of agroove, or a cavity, to be etched can be suitably dimensioned.